Systems and methods for assessing standoff capabilities of in-service power line insulators

ABSTRACT

An electrical power transmission system includes electrical insulators arranged to electrically isolate live power lines. Measurement devices are physically incorporated or integrated in the insulator structures. The measurement devices measure and report insulator properties during live wire conditions.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to and claims the benefit of theearliest available effective filing date(s) from the following listedapplication(s) (the “Related Applications”) (e.g., claims earliestavailable priority dates for other than provisional patent applicationsor claims benefits under 35 USC §119(e) for provisional patentapplications, for any and all parent, grandparent, great-grandparent,etc. applications of the Related Application(s)). All subject matter ofthe Related Applications and of any and all parent, grandparent,great-grandparent, etc. applications of the Related Applications isincorporated herein by reference to the extent such subject matter isnot inconsistent herewith.

RELATED APPLICATIONS

For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a divisional of U.S. patent application Ser. No.12/460,455, entitled SYSTEMS AND METHODS FOR ASSESSING STANDOFFCAPABILITIES OF IN-SERVICE POWER LINE INSULATORS, naming Roderick A.Hyde, Muriel Y. Ishikawa, Jordin T. Kare, David B. Tuckerman, Lowell L.Wood, Jr. and Victoria Y. H. Wood as inventors, filed on Jul. 17, 2009,which is currently co-pending, or is an application of which a currentlyco-pending application entitled to the benefit of the filing date.

1. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation-in-part of U.S. patentapplication Ser. No. 12/460,445, entitled SMART LINK COUPLED TO POWERLINE, naming Roderick A. Hyde, William Gates, Jordin T. Kare, Nathan P.Myhrvold, Clarence T. Tegreene, David B. Tuckerman and Lowell L. Wood,Jr. as inventors, filed on Jul. 17, 2009, which is currently co-pending,or is an application of which a currently co-pending applicationentitled to the benefit of the filing date.

2. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation-in-part of U.S. patentapplication Ser. No. 12/460,452, entitled MAINTAINING INSULATORS INPOWER TRANSMISSION SYSTEMS, naming Roderick A. Hyde, Muriel Y. Ishikawa,Jordin T. Kare, David B. Tuckerman, Lowell L. Wood, Jr. and Victoria Y.H. Wood as inventors, filed on Jul. 17, 2009, which is currentlyco-pending, or is an application of which a currently co-pendingapplication entitled to the benefit of the filing date.

The United States Patent Office (USPTO) has published a notice to theeffect that the USPTO's computer programs require that patent applicantsreference both a serial number and indicate whether an application is acontinuation or continuation-in-part. Stephen G. Kunin, Benefit ofPrior-Filed Application, USPTO Official Gazette Mar. 18, 2003, availableat http://www.uspto.gov/web/offices/com/sol/og/2003/week11/patbene.htm.The present Applicant Entity (hereinafter “Applicant”) has providedabove a specific reference to the application(s) from which priority isbeing claimed as recited by statute. Applicant understands that thestatute is unambiguous in its specific reference language and does notrequire either a serial number or any characterization, such as“continuation” or “continuation-in-part,” for claiming priority to U.S.patent applications. Notwithstanding the foregoing, Applicantunderstands that the USPTO's computer programs have certain data entryrequirements, and hence Applicant is designating the present applicationas a continuation-in-part of its parent applications as set forth above,but expressly points out that such designations are not to be construedin any way as any type of commentary and/or admission as to whether ornot the present application contains any new matter in addition to thematter of its parent application(s).

BACKGROUND

Power utilities generate electrical power at remote plants and deliverelectricity to residential, business or industrial customers viatransmission networks and distribution grids. The power utilities maytransmit large quantities of electric power over long distancetransmission networks from power generating plants to regionalsubstations, which then supply the power to local customers using thedistribution grids.

The transmission networks and/or distribution grids may include overheadpower transmission lines suspended by towers or poles. The transmissionlines may, for example, be bare wire conductors made of aluminum.Instead of aluminum, copper wires may be used in medium-voltagedistribution and low-voltage connections to customer premises.

Power loss in transmission lines (in particular, in long distancetransmission lines) is a significant component of the cost ofelectricity. This power loss is a decreasing function of transmissionvoltage. Therefore, power is typically first transmitted as high voltagetransmissions from the remote power plants to geographically diversesubstations. The most common transmission voltages in use are 765, 500,400, 220 kV, etc. Transmission voltages higher than 800 kV are also inuse. From the substations, the received power is sent using cables or“feeders” to local transformers that further reduce the voltage.Voltages below 69 kV are termed subtransmission or distributionvoltages. The outputs of the transformers are connected to a local lowvoltage power distribution grid that can be tapped directly by thecustomers.

The conductors in overhead power transmission lines are supported by orsuspended from insulators (e.g., by pin-type and suspension-typeinsulators, respectively). For subtransmission or distribution voltages,both types of insulators are commonly used in overhead powertransmission lines. However, for transmission voltages, onlysuspension-type insulators are commonly used in overhead powertransmission lines.

The mechanical and electrical qualities of the insulators in usedirectly affect the integrity of a suspended or supported overheadtransmission line. Insulators can fail, for example, because of surfacecontamination, aging, manufacturing defects and damage due tomishandling. Insulator failures are associated with a majority of lineoutages and most of line maintenance costs.

In practice, commercial electricity transmission networks anddistribution grids (collectively “the network” or “the grid”) may havecomplex topologies interconnecting several power plants, regionalsubstations, and load centers. The grid may include multiple redundantlines between network points or nodes so that power can be routed fromany power plant to any load center, through a variety of routes, based,for example, on network conditions, power quality, transmission patheconomics and power cost. Grid operators may control operation of thegrid by managing generators, switches, circuit breakers, relays, andloads. Industrial control system techniques may be used for thispurpose. For example, the grid may be coupled to common centralized,distributed or networked control systems (e.g., Supervisory control anddata acquisition systems (SCADA)), which electronically monitor andcontrol most or the entire grid. The electronic control actions may beperformed automatically by remote terminal units (“BTUs”) or byprogrammable logic controllers (“PLCs”). Communication in the controlsystems between different control elements and grid components may usemicrowaves, power line communication, wireless, and/or optical fibers.

“Smart” grids may further use modern digital technologies (e.g.,automation, sensing and measuring, and communication technologies) toupgrade distribution and long distance transmission grids. The digitaltechnologies may allow grid operations to be improved for increasedpower quality, reliability, efficiency, uptime, and safety. The digitaltechnologies may allow various distributed power generation and gridenergy storage options to be included in the grid, and reduce gridfailures (e.g., power grid cascading failures).

Consideration is now being given to improving electricity grids. Inparticular, consideration is now being given to solutions for keepinginsulators, which are in use in overhead power transmission systems,healthy. Some such solutions may prevent insulator failure and reduceline outages and/or line maintenance costs. Further, consideration isbeing given to improvements directed to alternate or non-traditionalgrid components for flexible management of grid operations.

SUMMARY

Approaches to maintaining power line insulators in a healthy state areprovided.

In an exemplary approach, a “self-conditioning” electrical insulator,which is configured to isolate a high-voltage power transmission line,includes an insulator body having a surface, a sensing unit arranged todetect a state of the surface, and a conditioner arranged to reconditionthe surface in response to the detected state of the surface. Theconditioner may be arranged to apply a coating (e.g., a resistive orhydrophobic coating) to at least a portion of the surface in response tothe detected state of the surface. The insulator may include one or moresheds each having an upper surface and a lower surface. The conditionermay be arranged to coat at least a portion of the upper surface and/orlower surface of the at least one shed in response to the detected stateof the surface. The coating which may be resistive and/or hydrophobicmay for example, include one or more of a hydrocarbon, silicone grease,a fluorocarbon and/or perfluoroheptane. An internal or external sourceof the coating materials may be suitably coupled to the conditioner. Theconditioner may spread the surface coating material over the insulatorsurface, for example, by lateral flow or extrude the surface coatingmaterial through the one or more pores on to at least a portion of thesurface.

The conditioner may be configured to apply the surface coating materialsafter the insulator surface has been cleaned manually or by some otherdevice. However, conditioner itself may be configured to clean at leasta portion of the surface by applying, for example, heat, electricalcurrent, ultrasound energy, or a surface cleaning material to thesurface. The conditioner may be arranged to spread the surface cleaningmaterial over the surface by lateral flow or by extrusion through one ormore pores onto the surface.

The sensing unit coupled to the insulator may be configured to detectsurface properties (e.g., surface wetness, dirt, resistivity, and/orleakage currents), weather events (e.g., precipitation, lightning,and/or pollution affecting the surface), and/or line events (e.g.,over-voltages and/or faults). The unit also may be configured to detecta time interval since a surface coating and/or a surface cleaning event,and to determine surface coating and/or cleaning times according to aschedule and/or user commands.

In another exemplary approach, a measurement device is arranged tomeasure properties of an insulator in use to isolate the powertransmission line. The measurement device may be physically incorporatedin or coupled to the insulator in use. The measurement device may beconfigured to conduct tests and measure insulator properties orparameters under live wire conditions. The measurement data may beacquired during short time intervals near voltage zero crossings in thepower transmission line. During such time intervals, the insulator maybe expected to be effectively decoupled from power flow in the powertransmission line and the measured data considered to be representativeof the individual insulator by itself.

The measurement data may be analyzed by a processing circuit to estimatepresent-time and predict future voltage standoff capabilities of theinsulators in use.

In additional or alternative approaches, devices and methods fordelivering high voltage electrical power are provided.

In an exemplary approach, a smart link is provided for use in a powerdelivery system. The smart link is configured to automatically isolateor insulate a power line, conduct, and or phase shift power on the line.

In another exemplary approach, an assembly includes a power-lineinsulator and a device disposed in parallel. The assembly furtherincludes a switch configured to establish a conducting path through thedevice bypassing the power-line insulator. At least a portion of thedevice and/or the switch may be co-disposed with the power-lineinsulator in a common physical structure. The device may be an activeimpedance module, a grounding switch, a lightning arrestor, a surgearrestor, an active grounding device, a dynamically insertable currentlimiter, an inverter, a transformerless reactive compensation device, aphase angle regulator, a variable series capacitor, a static VARcompensator, a varistor, a Zener diode, a nonlinear resistor, and/or abraking resistor. The device may be configured to inject power, sinkpower, and/or introduce impedance compensation in a power line and/orinsulator path in response, for example, to dynamic loading, transientvoltages and/or currents, phase conditions or other conditions on thepower line.

In yet another exemplary approach, a device includes an insulatorconfigured to electrically isolate a power line, and a switchableconductance coupled to insulator and placed in parallel with theinsulator. At least a portion of the switchable conductance may bedisposed within the insulator. The switchable conductance may includeone or more of a resistive device, resistor, varistor, a reactiveelement, an active impedance module, a grounding switch, a lightningarrestor, a surge arrestor, an active grounding device, a dynamicallyinsertable current limiter, an inverter, a transformerless reactivecompensation device, a phase angle regulator, a variable seriescapacitor, a static VAR compensator, a braking resistor, and/or othercircuit elements.

The switchable conductance may be configured to divert a current aroundthe insulator in response, for example, to a breakdown and/or ananticipated breakdown of the insulator, a rise and/or a predicted risein voltage across the insulator, and/or measured power line parametervalues, an environmental event and/or predicted environmental eventproximate and/or remote to the device. The switchable conductance may becoupled to a heat sink made of materials that absorb heat by phasechange.

In a further exemplary approach, a method includes deploying aninsulator assembly having two switchable states—an insulator state and aparallel device state, to electrically isolate a power line, sensing apower line condition or parameter, and

in response, switching the insulator assembly to its parallel devicestate to source, sink, and/or dispatch real and/or reactive power on thepower line.

In yet another exemplary approach, a method includes disposing apower-line insulator and a device in parallel, and providing a switchconfigured to establish a conducting path through the device bypassingthe power-line insulator. The switch may be actively switchable inresponse to a power line condition or parameter. The device, which maybe directly or indirectly coupled to a power line, may carry real and/orreactive currents in its active state. The device may be configured toinject power into and/or sink power from a power line, introducecompensation in a power line and/or insulator path to control currentvalues, and/or regulate an equivalent reactance of a power line and/orsuppress power oscillations in the power line.

In still another exemplary approach, a method includes providing aninsulator to electrically isolate a power line, and providing aswitchable parallel conductance coupled to insulator. The switchableconductance may include a resistive device, a resistor and/or varistor,an active impedance module, a grounding switch, a lightning arrestor, asurge arrestor, an active grounding method, a dynamically insertablecurrent limiter, an inverter, a transformerless reactive compensationmethod, a phase angle regulator, a variable series capacitor, a staticVAR compensator, a varistor, a Zener diode, a nonlinear resistor, and/ora braking resistor. The method further includes switching the switchableconductance on or closed in an active state and diverting a currentaround the insulator. Heat generated by the current flow may be absorbedby a heat sink made of material that absorbs heat by phase change.

BRIEF DESCRIPTION OF THE FIGURES

In the accompanying drawings:

FIGS. 1A and 1B are illustrations of exemplary pin-type andsuspension-type insulators;

FIG. 1C is an illustration of an exemplary power transmission tower fromwhich power lines are supported by suspension-type insulators;

FIG. 1C shows exemplary power transmission lines, in accordance with theprinciples of the solutions described herein;

FIG. 2 is a block diagram illustrating components of an exemplary powertransmission line system, in accordance with the principles of thesolutions described herein;

FIG. 3 is a schematic illustration of an exemplary power line insulatorhaving self-reconditioning features, in accordance with the principlesof the solutions described herein;

FIG. 4 is a flow diagram illustrating an exemplary method formaintaining power line insulators in a healthy state, in accordance withthe principles of the solutions described herein;

FIG. 5 is a block diagram illustrating components of another exemplarypower transmission line system, in accordance with the principles of thesolutions described herein;

FIG. 6 is a schematic illustration of an exemplary power line insulatorcoupled to measurement probes for assessing insulator standoffcapabilities, in accordance with the principles of the solutionsdescribed herein;

FIG. 7 is a flow diagram illustrating an exemplary method for assessinginsulator standoff capabilities, in accordance with the principles ofthe solutions described herein;

FIG. 8 is a schematic illustration of a portion of an electricity gridhaving two ac line or paths leading from a power source to a load;

FIG. 9A is a block diagram illustrating an exemplary smart link orintegrated insulator assembly including an insulator and a device, whichcan be passively or actively switched between two states, in accordancewith the principles of the solutions described herein;

FIG. 9B is a block diagram illustrating exemplary components of thedevice of FIG. 9A, in accordance with the principles of the solutionsdescribed herein;

FIG. 10 is a block diagram illustrating exemplary components of a smartpower delivery system, in accordance with the principles of thesolutions described herein;

FIG. 11 is a flow diagram illustrating an exemplary method for smartpower delivery, in accordance with the principles of the solutionsdescribed herein;

FIG. 12 is a block diagram illustrating an exemplary power line systemcomponent having temperature control or limiting features, in accordancewith the principles of the solutions described herein;

FIGS. 13A and B are a schematic diagram illustrating exemplary insulatorcomponents having various combinations of inductive elements and/orreactive elements and an insulator body, in accordance with theprinciples of the solutions described herein;

FIG. 13C is a flow diagram illustrating an exemplary method fordispatching power over a multi-line power delivery system, in accordancewith the principles of the solutions described herein;

FIG. 14A is a block diagram illustrating exemplary components of a powerdelivery system, in accordance with the principles of the solutionsdescribed herein;

FIG. 14B is a flow diagram illustrating an exemplary method foroperating a power delivery system which uses insulator element/reactivecircuit combinations to electrically isolate a high voltage powertransmission line, in accordance with the principles of the solutionsdescribed herein; and

FIG. 15 is a flow diagram illustrating an exemplary method fordispatching power over a multi-line power delivery system, in accordancewith the principles of the solutions described herein.

Throughout the figures, unless otherwise stated, the same referencenumerals and characters are used to denote like features, elements,components, or portions of the illustrated embodiments.

DESCRIPTION

In the following description of exemplary embodiments, reference is madeto the accompanying drawings, which form a part hereof. It will beunderstood that embodiments described herein are exemplary, but are notmeant to be limiting. Further, it will be appreciated that the solutionsdescribed herein can be practiced or implemented by other than thedescribed embodiments. Modified embodiments or alternate embodiments maybe utilized, in the spirit and scope of the solutions described herein.

FIGS. 1A and 1B show exemplary pin-type and suspension type insulators100A and 100B, respectively, which may be deployed in an overhead powertransmission line. The insulators may be made, for example, fromwet-process porcelain, toughened glass, glass-reinforced polymercomposites or other non-ceramic materials. Porcelain insulators may havea semi-conductive glaze finish, so that a small current (a fewmilliamperes) passes through the insulator. This warms the surfaceslightly and reduces the effect of fog and dirt accumulation. Thesemiconducting glaze also insures a more even distribution of voltagealong the length of the chain of insulator units 102.

FIG. 1C shows exemplary power transmission lines 110 supported from atower 120 by suspension type insulators 130. Insulators 130 may be madeof one or more insulator disks 130A. The number of disks 130A in anyparticular insulator 130 deployed to support lines 110 from tower 120may be selected in consideration of the line voltages, lightningwithstand requirements, altitude, and environmental factors such as fog,pollution, or salt spray. The number of disks may be increased to obtainlonger insulators 130 having longer creepage distance for leakagecurrents along insulator surfaces. Further, insulators 130 may beselected to be strong enough to mechanically support the weight of thesupported line, as well as loads due to ice accumulation, and wind.

Approaches for avoiding line outages and/or reducing line maintenancecosts include keeping line insulators in a healthy state even as theyare in service under energized, live or hot line conditions.

In an exemplary approach for avoiding line outages and/or reducing linemaintenance costs, a power transmission line system includes a mechanismfor automatically reconditioning insulator surfaces to mitigate thedeleterious effects of fog, salt spray, pollution and/or dirtaccumulation on insulator performance or lifetime. The system mayinclude one or more electrical insulators arranged to electricallyisolate a power line, and an insulator surface conditioner arranged torecondition the surface of an electrical insulator in use (i.e., underlive wire conditions). The conditioner may be arranged to clean and/orapply a coating (e.g., a resistive and/or hydrophobic coating) to thesurface. The coating may, for example, be any suitable current-impedingcoating. The coating materials (e.g., a hydrocarbon, silicone grease, afluorocarbon and/or perfluoroheptane) may be obtained from a source orreservoir coupled to the conditioner. Likewise, cleaning materials(e.g., detergents, solvents, surfactants, etc.) may be obtained from asource or reservoir coupled to the conditioner. The sources may beconfigured to deliver the coating materials and cleaning materials overthe surface by lateral flow or by extrusion through pores or openings inthe insulator surface.

Instead or in addition to applying cleaning fluids, the conditioner maybe arranged to apply heat, electrical current, ultrasound or other formsof energy to clean or recondition the insulator surfaces. The surfacecleaning energy may be applied in conjunction with application ofcleaning fluids and/or coating materials. The system may further includea component for collecting and/or disposing reconditioning processresidues.

The conditioner may recondition the surface of the electrical insulatoron user command, on a suitable time schedule or in response to adetected insulator surface condition or line event. For this purpose thesystem may include a sensing unit arranged to detect a state of theinsulator surface (e.g., surface wetness, dirt, resistivity, and/orleakage currents), line events (e.g., line faults and over voltages)and/or environmental conditions (e.g., precipitation, lightning, and/orpollution affecting the surface). Further, the system may include atimer configured, for example, to detect a time interval since aprevious surface coating and/or a surface cleaning event. The sensingunit also may be configured to report system status including forexample, conditioner status, and information on one or more of presentsurface conditions, pre- and post-reconditioning event surfaceconditions, and the timing and completion of reconditioning events.

FIG. 2 shows an exemplary power transmission line system 200 having“self-reconditioning” insulators. System 200 includes power transmissionlines 210 supported by insulators 220, which are coupled to an insulatorsurface reconditioner 230. System 200 may include a controller 250configured to coordinate operation of surface reconditioner 230 to keepthe surfaces in good insulating condition. System 200 may also include asensor arrangement 240 configured to monitor insulator, line conditionsand/or weather conditions. Sensor arrangement 240 may generateappropriate reporting signals to controller 250, surface reconditioner230 and/or other external devices.

Surface reconditioner 230 may be configured to prime or clean theinsulator surfaces by treating the surfaces with suitable priming orcleaning materials and/or energy. For example, surface reconditioner 230may clean insulator surface portions by controllably applying cleaningor washing fluids to the surface portions. The cleaning or washingfluids may include chemical and/or physical cleaning agents (e.g.,chemical solutions or gels, detergents, surfactants, compressed gassesetc.). The cleaning fluids may be naturally deposited rain water. A flowof fluids across an insulator surface portion may be driven by surfacetension. An insulator surface portion may be structured to create asurface energy gradient so that flow of cleaning or washing fluids (andother fluids/coating materials) over the portion of the surface isdriven by the surface energy gradient.

Additionally or alternatively, surface reconditioner 230 may cleaninsulator surface portions by controllably applying heat (e.g.,resistive heat) and/or radiation (e.g., UV, ultrasound, light) to thesurface portions. Alternatively or additionally, surface reconditioner230 may resurface the insulator surfaces or portions thereof with aninsulating, resistive or other protective coating material (e.g., asilicone grease, fluorocarbons, pefluoroheptane, etc.). The coating maybe applied with or without previous priming or cleaning of the insulatorsurfaces. Further, the previous priming or cleaning of the insulatorsurfaces may be implemented manually or using other devicesindependently of system 200.

Sensor arrangement 240 may include suitable sensors to detect, forexample, conductive or dirty regions of the insulator surfaces,weather-related events (e.g., snow, ice or rain) and/or line events(after over-voltages, faults, etc.). Sensor arrangement 240 may includeone or more of optical, chemical, electrical and/or mechanical sensors.Sensor arrangement 240 may also be configured to report a cleanlinessstatus of the insulator, for example, to controller 250 and/or otherexternal devices. Further, sensor arrangement 240 may be configured tomeasure a physical and/or electrical status of coating materials presenton the insulator surfaces, and to report such status to other componentsof system 200 or other external devices.

In response to suitable sensor signals and/or external commands, surfacereconditioner 230 may clean and/or resurface the insulator surfaces.Surface reconditioner 230 may clean and/or resurface all insulatorsurfaces or only limited portions (e.g., dirty or conductive portions)thereof. Surface reconditioner 230 may clean and/or resurface theinsulator surfaces on a time schedule or in a continuous mode.

One or more components of surface reconditioner 230 (e.g., fluidreservoirs, pumps, etc.) in system 200 may be placed in or about theinsulator body (e.g., in physical cavities or portions of the insulatorbody). Alternatively or additionally, one or more components of surfacereconditioner 230 may be placed in operational proximity to theinsulator body (e.g., on tower 120). Likewise, one or more components ofcontroller 250 and sensor arrangement 240 may be disposed in or aboutthe insulator body or at other locations.

Controller 250 may be configured to supervise operation of system 200including surface reconditioner 230. Controller 250 may have anysuitable mechanical or electromechanical structure, and include anoptional programmable interface. In operation, controller 250 maycontrol timing and extent of reconditioning processes performed bysurface reconditioner 230. For example, controller 250 may control theamounts of coating and/or cleaning fluids released by surfacereconditioner 230 in response to one or more event-triggered controlsignals. The event-triggered control signals may be generated by one ormore control elements. The control elements may include sensors ofsensing arrangement 240, a timer and/or a user-activated switch (notshown). Like the components of surface reconditioner 230 and sensingarrangement 240, control elements and other components of controller 250may be disposed either inside or outside the insulator body. One or morecontroller 250 components may, for example, be located in a remotebuilding or facility, for example, and linked through wireless, wired,IP protocol or other approaches.

FIG. 3 shows an exemplary insulator 300 having three insulator disks orsheds 302-306. Insulator 300 includes surface reconditioner components230A-230D and sensor 240 incorporated in portions of the insulator body.

Component 230A may, for example, be an energy-emitting device (e.g., UV,or infrared device) placed underneath insulator shed 302. Component 230Amay be configured to illuminate top surface 304S of underlying insulatorshed 304 with surface cleaning energy. The surface cleaning energy mayremove or reduce pollutant accumulations or deposits on surface 304S by,for example, thermal, ultrasonic, or photo-chemical action. Component230B may, for example, be a pressurized reservoir or source of siliconegrease and/or cleaning fluids. Component 230B may be disposed above shed302 to release the silicone grease and/or cleaning fluids throughopenings (not shown) on to top surface 302S. Further, component 230Cdisposed, for example, in shed 304 may, include a pair of electrodes Aand B. Component 230C may be configured to remove or reduce pollutantaccumulations or deposits on outer surfaces 306S of shed 306electrically by passing a surface current between electrodes A and B.Component 230D may, for example, be an ultrasound energy-emittingdevice. Component 230D may be configured to remove or reduce pollutantaccumulations or deposits on surface 304S by ultrasonic action.

In general surface reconditioner 230 may be configured to apply thecleaning and coating materials by extruding the materials either over abroad area of an insulator surface or a limited area. The materials maybe supplied from either internal or external reservoirs/sources. In anexemplary embodiment, a flow of the materials across an insulatorsurface portion may be driven by surface tension. An insulator surfaceportion may be structured to create a surface energy gradient so thatflow of the materials over the portion of the surface is driven by thesurface energy gradient.

One or more components 230A-D of surface reconditioner 230 may bearranged to operate in open-loop configurations. Alternatively, one ormore components 230A-D of surface reconditioner 230 may be configured tooperate in closed-loop configurations in conjunction with, for example,a feed back sensor signal generated by sensor arrangement 240. Surfacereconditioner 230 may resurface insulator surfaces in response to asensed surface state (wetness, dirt, cleanliness, resistivity, leakagecurrents, etc.), environmental conditions (e.g., precipitation,lightning, pollution, etc.), line events (over-voltages, faults, etc.).

The resurfacing of the insulator surfaces (e.g., cleaning, primingand/or recoating) by surface reconditioner 230 may extend over the fullsurface or be limited to a region of the surface. Regional resurfacingmay be based on local surface conditions, or upon a schedule. Theresurfacing materials and/or energy may be applied uniformly to thesurface region (e.g., via extrusion through a porous surface) or mayresult from lateral flow of fluids from localized sources/reservoirs atan edge of the surface region.

Surface reconditioner 230 may be configured to remove existing insulatorsurface coatings. Surface reconditioner 230 may remove the existingcoatings using suitable cleaning fluids, heat, ultrasonic energy, and/orsuitable photo-driven breakdown. System 200/surface reconditioner 230may be further configured to collect the removed old coating material(e.g., by gravity flow, in the case of fluid removed coatings). The oldcoating materials may be discarded, kept for analysis, or recycled.

Components and subcomponents of surface reconditioner 230; sensorarrangement 240, and other internal or external devices (e.g.,controller 250, status indicators etc.) may be interconnected using anysuitable approaches including, for example, optical, electrical,pneumatic, and/or mechanical approaches.

FIG. 4 shows exemplary features of a method 400 for maintainingin-service power transmission line insulators in a healthy state. Method400 involves reconditioning insulator surfaces under live wireconditions. Method 400 includes determining a condition of a surface ofan insulator supporting a live power transmission line (410), andaccordingly reconditioning at least a portion of the insulator surface(420) to maintain the in-service insulator in a healthy state.

Reconditioning the insulator surface may involve applying a coating(e.g., a resistive, hydrophobic or other protective coating) to at leasta portion of the surface. The coating materials may include one or moreof a hydrocarbon, silicone grease, a fluorocarbon and/orperfluoroheptane. Method 400 includes obtaining such coating materialsfrom sources coupled to the electrical insulator, and laterally flowingthe coating materials over at least a portion of the surface orextruding the coating materials though the one or more pores on to atleast a portion of the surface. Additionally or alternatively,reconditioning the insulator surface may involve cleaning or priming theinsulator surface. In method 400, cleaning or priming the insulatorsurface may include applying heat, an electrical current, ultrasoundenergy other energy and/or a surface cleaning material from a sourcecoupled to the electrical insulator. Like the coating materials, thesurface cleaner materials may be laterally flowed and/or extrudedthrough the pores onto at least a portion of the surface.

In method 400, the surface reconditioning processes (e.g., coating,cleaning or priming operations) are carried out automatically inresponse to a determined state of a surface of an insulator supporting alive power transmission line (410). Method 400 may include physicallycollecting and/or disposing reconditioning process residues. Further,determining a state of a surface of an electrical insulator may includedetecting one or more of surface conditions (e.g., surface wetness,dirt, resistivity, and/or leakage currents), environmental or weatherconditions (e.g., precipitation, lightning, and/or pollution affectingthe surface) and/or line events (e.g., over-voltages or line faults).Additionally or alternatively, determining a state of a surface mayinclude detecting a time interval since a previous surfacereconditioning event, determining a surface coating and/or cleaning timeaccording to a schedule and/or a user initiated command signal.

Further, method 400 may include reporting surface conditions beforeand/or a reconditioning event, reporting information on one or more ofcurrent surface conditions, timing and completion of reconditioningevents.

In another exemplary approach for avoiding unplanned line outages and/orreducing line maintenance costs, a power transmission line systemincludes capabilities for assessing changes in the standoff capabilityof in-service insulators. The results of such monitoring may helpestablish maintenance and insulator replacement schedules to reduceunplanned outages and line maintenance costs.

Voluntary industry standards have been established for testing andqualifying insulators for use in power transmission systems. Forexample, Institute of Electrical and Electronic Engineers standard:“IEEE 1024-1988” recommends practice for distribution suspension typecomposite insulators made from a core, weathersheds, and metal endfittings that are used in the distribution of electric energy. Therecommendation contains several design tests that are unique tocomposite insulators. Further, for example, American National StandardsInstitute (ANSI) standard: “ANSI C29.11 Composite Suspension Insulatorsfor Overhead Transmission Lines-Tests”, describes tests and acceptancecriteria for composite insulators for applications above 70 kV. OtherANSI standards in the C29 series are for insulators made of wet-processporcelain or toughened glass. Further, for example, InternationalElectrotechnical Commission (IEC) standard: “IEC 1109: Compositeinsulators for a.c. overhead lines with a nominal voltage greater than1000 V-Definitions, test methods and acceptance criteria,” describestests and acceptance criteria for composite insulators for applicationsabove 1 kV. Other IEC standards (e.g., IEC 383, IEC 437: Report—radiointerference test on high-voltage insulators, IEC 507: Report—artificialpollution tests on high-voltage insulators to be used on a.c. systems,IEC 60060-1 and IEC 60060-2, etc.) set forth test and acceptancecriteria for other insulator types and use conditions. All of theaforementioned industry standards are incorporated by reference in theirentireties herein.

The voluntary industry standard tests and characteristics are intendedto give a common base to designers, users and suppliers of overheadlines, insulators and line equipment when definition, evaluation orverification of the electrical characteristics of such equipment isrequired.

The voluntary industry standard tests and characteristics relate topower line insulators under defined test conditions before theinsulators are deployed in power transmission systems. However,insulators can degrade or deteriorate in use. An insulator may developimpurities, cracks or other defects which limit its ability to withstandelectrical potential. Degrading influences may include contamination ofinsulator surfaces with chemicals from the surrounding atmosphere thatattack and destroy the molecular structure, and physical damage due toimproper handling or accidental shock, vibration and excessive heat.Further, voltage transients in the conductors inside the insulators thatare caused, for example, by power surges or spikes can lower thedielectric strength to the point of failure. The degrading influencesmay result in more leakage current through the insulator, which may beindicative of impending insulator failure.

In the exemplary monitoring approach, standoff capability measurementdevices, probes and sensors (collectively “measurement devices”) arephysically integrated with insulator bodies and/or place in closeproximity thereto. The measurement devices may be configured to test,measure, or monitor selected insulator properties (e.g., surfaceresistivity/conductivity, leakage currents, electric fields, etc.) thatrelate to the insulators' standoff capabilities under live conditions.The testing by the measurement devices may include any suitable test ortests of insulator characteristics and properties. The tests mayoptionally include one or more tests of insulator characteristics thatare the same or similar to those described in the voluntary industrystandards for insulator testing. The measurement devices may apply zero,low and/or high-frequency test fields/voltages to an insulator or aportion thereof for testing purposes. Further, the measurement devicesmay be configured to detect environmental events (e.g., rain, snow,lightning, pollution, etc.) and line events (e.g., faults).

A local or remote signal or data processing circuit coupled to themeasurement devices may log and/or process measurement device data. Theprocessing circuit may, for example, include algorithms or routines forpredicting insulator characteristics and behavior based on the measuredinsulator properties and/or environmental events. The processing circuitmay be configured to report the measured and/or predicted insulatorcharacteristics and behavior to a controller or other user. Theprocessing circuit may be configured to generate reports based on aschedule, and/or in response to a query or event (e.g., a weather eventsuch as rain/snow/lightning, or an insulator characteristic valueevent).

FIG. 5 shows an exemplary power transmission line system 500 includingcapabilities for monitoring and predicting insulator standoffcapabilities of in-service insulators. System 500 includes powertransmission lines 510 supported by insulators 520, which are coupled tomeasurement devices, probes and sensors (“measurement devices” 530).Measurement devices 530 may be coupled to a signal or data processingcircuit 540. Further, system 500 may include a controller 550 configuredto coordinate operation of measurement devices 530, processing circuit540 and other internal and external devices.

Measurement devices 530 may include sensors (e.g., sensor arrangement240) configured to monitor insulator, line conditions and/or weatherconditions or events. Further, measurement devices 530 may includeelectrical, chemical, mechanical, optical, and/or other types of devicesor probes, which are configured to suitably test electrical andmechanical characteristics or properties of in-service insulators insystem 500. The devices or probes may include, for example, electronicdevices (e.g., ohmmeters, ammeters, voltmeters, magneto-optic devices,opto-electric devices, capacitances, resistors, etc.), mechanicaldevices (switches, shunts), and/or optical devices (e.g., magneto-opticcurrent transducers, opto-electric imagers, etc.) The measuredproperties may, for example, include one or more of absorption currents,capacitive charging currents, leakage currents, capacitance, resistance(e.g., single or spot megaohm readings), dielectric absorption (DA),polarization index (PI), high potential or hipot (high voltage) and stepvoltage responses, switching or lightning impulse voltage responses,and/or temperature.

The measurements by measurement devices 530 may involve application ofsuitable voltages to the insulator or portions of the insulator. Thetesting voltages applied to the insulator or portions of the insulatormay be DC voltages or AC voltages. The AC voltages may, for example, beat a nominal line frequency or at higher frequencies. For example,dielectric absorption (DA) testing, which is a measure of the ability ofthe insulator under test to withstand high voltage without breakdown,involves the application of a predetermined value of DC voltage for aperiod of one minute. The measurement voltages may be derived formsuitable power sources internal or external to the insulator. Forexample, the power sources may be voltage/current transformers coupledto a power line. (See e.g., U.S. Pat. No. 4,823,022, which describes acurrent transformer and/or a voltage transformer embedded in a powerline supporting insulator to form an integral unit therewith.)

One or more measurement devices 530 may be configured to conduct Hipotor over-potential testing, which involves the application of apredetermined AC or DC over-voltage to determine if that voltage can besuccessfully withstood or if defects exist in the insulator, by applyingtest voltages to the insulator segment by segment. For example, eachinsulator disk or shed in a string of insulator disks may be tested oneby one. Likewise, step voltage or leakage current vs. voltage testing ofthe insulator, which involves applying a DC test voltage for a specificamount of time and recording the leakage current at scheduled times(e.g., after 60 seconds) for a series of voltage steps up to apredetermined level of voltage, may be conducted on insulator segment bysegment.

Additionally or alternatively, one or more measurement devices 530 maybe configured to conduct a resistivity, a breakdown voltage, a voltageresponse, and/or water penetration tests including hardness, steep-frontimpulse voltage, and power frequency voltage tests in under appropriateweather conditions (e.g., rain). Further, one or more measurementdevices 530 may be configured to conduct low-frequency dry flashovertests, low-frequency wet flashover tests, critical impulse flashovertests, radio-influence voltage and salt fog-like tests. Measurementdevices 530 (e.g., imagers) also may be used to optically evaluateinsulator surface properties (e.g., discoloration, chalking, crazing,dry bands, tracking and erosion) related to material ageing.

Components and subcomponents of measurement devices 530 may beinterconnected to processing circuit 540 and other internal or externaldevices (e.g., controller 550, status indicators, displays, etc.) usingany suitable approaches including optical, electrical, wireless,pneumatic, and/or mechanical approaches. Processing circuit 540 may beconfigured to receive and process data and/or signals from one or moremeasurement devices 530 over the interconnections. Processing circuit540 may include any suitable combination of hardware and software forprocessing the data and/or signals. Processing circuit 540 may includean algorithm or routine configured to compute a present-time standoffvoltage capability of an insulator in system 500. The algorithm maygenerate a present-time standoff voltage capability based, for example,on live data and/or signals received from measurement devices 530 and/orhistorical measurement data. Processing circuit 540 may further includea predictive algorithm or routine configured to predict or forecastfuture standoff voltage capability of the insulator based, for example,on trends or events in historical measurement data. The predictivealgorithm may be configured to predict a time to failure estimate forthe insulator. The predicted standoff voltage capability and time tofailure values may include consideration of factors such as insulatorage, and/or weather conditions, etc. Processing circuit 540 may includeor have access to lookup tables and formulas for computing values fordifferent conditions.

Processing circuit 540 may be configured to report measurement data andprocessing results to other devices (e.g., controller 550) and/or users.Processing circuit 540 may be configured to report measurement data andprocessing results according to a schedule, in response to a query, inresponse to environmental event, or in response to measured or predictedvalues crossing preset thresholds.

Optional controller 550 may be configured to supervise operation ofsystem 500 including measurement devices 530 and processing circuit 540.Controller 550 may have any suitable mechanical or electromechanicalstructure, and include an optional user interface. In operation,controller 550 may control timing and extent of measurements performedby measurement devices 530 and data and/or signal processing byprocessing circuit 540. For example, controller 550 may initiatemeasurements by measurement devices 530 in response to one or moreevent-triggered control signals. The event-triggered control signals maybe generated by one or more control elements. The control elements mayinclude sensors in measurement devices 540 or other sensors (e.g.,sensor arrangement 240, FIG. 2), a timer and/or a user-activated switch(not shown).

One or more components or portions of system 500 including measuringdevices 530, processing circuit 540 and controller 550 may be placed inor about the insulator structure (e.g., in physical cavities or portionsof the insulator body). Alternatively or additionally, one or morecomponents or portions of system 500 may be placed in operationalproximity to the insulator body (e.g., on tower 120, or on insulatordisk connectors) or at remote locations. One or more components ofprocessing circuit 540 and/or controller 550 may, for example, belocated in a remote building or facility and linked with system 500components through wireless, wired, IP protocol or other approaches.

FIG. 6 shows an exemplary insulator 600 that may be used in system 500.Insulator 600 may have several insulator disks or sheds (e.g., sheds602-606) strung together. Insulator 600 includes measuring devices 530and other structures for assessing, detecting and reporting the standoffcapabilities of insulator 600 in service. Measuring devices 530 may belinked to a data and/or signal processing circuit 540A/B and otherdevices (e.g., controller 550) via wired or wireless electrical, and/oroptical links (e.g., via optical fiber 605). Measuring devices 530,processing circuit 540A-B, and the other structures may be physicallydisposed wholly or in part within the insulator body or at locationsexternal to the insulator body. FIG. 6 shows, for example, measurementdevices 530 disposed within insulator 600, processing circuit component540A disposed on top of insulator 600, and processing circuit component540B disposed at an external location.

FIG. 6 further shows, for example, measurement devices 530 as includinga megohmeter 630, which is configured to be switchably connected acrossa portion of the insulator body (e.g., shed 602) to measure theportion's resistivity. Megohmeter 630 includes megohmeter probes A andB, which may be configured to be connected to electrodes E on eitherside of shed 602 by switches S. Switches S may, for example, bemechanical or electronically operable switches, which may operate underthe supervision of processing circuit 540A/B and/or controller 550. Wheninsulator 600 is deployed in system 500, megohmeter 630 may, forexample, provide resistivity data that can be processed to assessinsulator standoff voltage capability in real time and to predict timeto failure.

FIG. 7 shows exemplary features of a method 700 for assessing thestandoff voltage capabilities of in-service power transmission lineinsulators. Method 700 includes arranging a measurement device inphysical contact with an insulator in use to electrically isolate apower transmission line (710), and measuring properties of the insulatorin use with the measurement device (720). At least a part of themeasuring device is disposed within the structure or body of theinsulator.

In method 700, measuring properties of the insulator in use with themeasurement device may include measuring one or more of absorptioncurrents, capacitive charging currents, leakage currents, capacitance,resistance, dielectric absorption (DA), polarization index (PI), highpotential or hipot (high voltage) and step voltage responses, switchingor lightning impulse voltage responses, and/or temperature. Further,measuring properties of the insulator in use with the measurement devicemay include conducting water penetration tests including one or more ofhardness, steep-front impulse voltage, and power frequency voltagetests, and conducting one or more of low-frequency dry flashover tests,low-frequency wet flashover tests, critical impulse flashover tests,radio-influence voltage and/or salt fog-like tests on the insulator inuse. Measuring properties of the insulator in use with the measurementdevice may also include optically evaluating surface propertiesincluding one or more of chalking, crazing, dry bands, tracking and/orerosion of the insulator in use. The measured properties may include DCproperties and frequency-dependent properties of the insulator in use.The properties may be measured under test excitations at, below, orabove a nominal power line frequency.

Method 700 may further include estimating a present-time and/or afuture-time standoff voltage capability of the insulator, and/or atime-to-failure based on insulator properties measured by themeasurement device and generating a recommended maintenance schedule forthe insulator in use (730).

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.For example, the systems and methods described herein may include a testof insulator properties in response to a pulsed electric field ofvariable amplitude applied to an in-service insulator (e.g., insulator130, FIG. 1C) at about a power line's (e.g., power line 110, FIG. 1C)voltage zero-crossing time-points. In the test, the pulsed electricfield may be applied between the insulator's power line-gripping point(130C) and the local tower-arm (130T) to which the insulator isattached. The test may involve measuring the responsive (leakage)current flow through the insulator over a short time scale (e.g.,˜microsecond). Such a short time scale, which is short compared to avoltage cycle in the power line (˜1/power line frequency), may besufficiently long for avalanching processes initiated by the appliedelectrical pulse to complete at atmospheric pressure. Any incipientelectrical discharge resulting from application of the pulsed electricfield in this manner may be expected to be quenched before thepower-line voltage swings high. The short time-scale-of-testing mayexploit the power lines' high inductance to effectively decouple thetest-point of the insulator (e.g., 130C) from almost all of the powerline (except possibly for a short local section). This manner ofin-service testing of the voltage stand-off capability of in-serviceinsulator 130 may allow power transmission line 110 to be exercised upto almost all of its present-time maximum voltage rating (e.g., up to90%). Processing circuit 540 may be configured to compute an estimatedvoltage stand-off capability for the particular insulator based on themeasured currents in response to the variable amplitude electricalpulses, and also to report the insulator capability in real time, forexample, for real time management of power loads in the powertransmission system.

An exemplary electricity network or grid delivers power from diversecentralized sources (e.g., hydroelectric, nuclear and coal power plants)and distributed sources (e.g., wind farms and solar photovoltaic arrays)to industrial and retail customers. In practice, the electricity networkor grid may have complex topologies including multiple paths, loops, andbottlenecks that lead to inefficient use of grid infrastructure. Theelectricity network or grid may, for example, include multiple redundantlines between points on the network so that power can be routed from anypower plant to any load center, through a variety of routes based on theeconomics of the transmission path and the cost of power.

FIG. 8 shows, for example, a portion of an electricity grid 800 havingtwo ac lines or paths 810 and 820 leading from a power source 830 to aload 840. The power flow over each ac line path is a function of lineend voltages, phase angle and line impedance. In an unmanaged oruncontrolled grid 100, electricity may, for example, flow from source830 to load 840 along both paths 810 and 820 in inverse proportion tothe relative impedances of the two transmission paths.

In a managed or controlled grid, it may be possible to vary parameters(e.g., series impedance, shunt impedance, phase angle, and occurrence ofsub harmonic oscillations), which influence power flow in a particulartransmission line. For example, grid 800 may include legacy mechanicalcontrollers (e.g., mechanically switched devices such as tap changers,phase shifters, switched capacitors and reactors (inductance)) thatallow control of the parameters affecting the power system. However, themechanical controllers do not provide high speed control, and are proneto breakdown if used frequently. Alternatively of additionally, grid 800may include electronic controllers (e.g., thyristor-based devices,high-speed phase angle regulators, high-speed variable seriescapacitors, varistors, Zener diodes, nonlinear resistors, static VARcompensators, braking resistors, etc.) that allow control of one or moreAC transmission line parameters. Unlike the mechanical controllers, maybe operated to provide high-speed control. The electronic controllershave been proposed for, or deployed in, recent grid installations toprovide reactive power compensation (e.g., series inductivecompensation, series capacitive compensation, and/or shunt compensation)for better and reliable grid utilization. While most common electroniccontroller devices (e.g., high-speed phase angle regulators, high-speedvariable series capacitors, Static VAR compensators, braking resistors,etc.) are thyristor based, other electronic controller devices may bebased on other semiconductor devices (e.g., BJTs, MOSFETs, and IGBTs,etc.).

In an exemplary approach for electronic control of electricity grids ornetworks, a multi-purpose electrical device (hereinafter “smart link”)is provided. A single or integrated smart link may be configured toperform different electrical functions or tasks in an electricity gridor network at different times or conditions. For example, a single smartlink may be configured to operate variously as an ordinary lineinsulator and as a conductor. FIG. 9A shows an exemplary smart link orintegrated insulator assembly 900, which can be passively or activelyswitched between two states by switch S. A high voltage end H ofinsulator assembly 900 may support or suspend a power line 910.Insulator assembly 900 may be coupled to power line 910 directly orindirectly (e.g., via transformer). A low voltage end L of insulatorassembly 900 may be connected to ground, for example, via a tower arm(FIG. 8). Alternatively, low voltage end E of insulator assembly 900 maybe connected to a like low voltage end of an insulator orinsulator-assembly supporting another phase line.

In a first or normal state, insulator assembly 900 functions as asuspension (or strut) insulator 920 for electrically isolating powerline 910. In a second or activated state, insulator assembly 900functions, for example, as a device 930 that provides a parallelelectrical path from high voltage end H to low voltage end E around orbypassing insulator 920.

Device 930 may be configured to carry real and/or reactive currents toor from power line 910. Device 930 may include any suitable switchgearcircuits made of interconnected electrical and/or electronic elementssuch as resistors, reactors, capacitors, inductors, transistors,thyristors, EMF sources, and/or sinks, etc. The switchgear circuits maybe arranged to carry real and/or reactive currents transiently orcontinuously.

It will be understood that insulator 920 and device 930 are shownschematically in FIG. 9A as separate blocks only for convenience andease of visualization. In practice, one or more elements or componentsof insulator 920 and device 930 (e.g., resistive or reactive elements)may be physically integrated and co-disposed in insulator assembly 900.Additionally or alternatively, one or more elements or components ofinsulator 920 and device 930 may be lumped at discrete locations withinsuch an assembly. Further, one or more elements or components of device930 (e.g., reactive elements) may be distributed along power line 910.

In an exemplary implementation of insulator assembly 900, the switchgearcircuits of device 930 may include one or more grounding switchesintegrated with insulator 920. The grounding switches may be arranged toground or divert currents from flowing through insulator 920, forexample, in case of line and/or insulator fault. The grounding switchesmay have functionalities that are the same or similar to thefunctionalities as the grounding switches described, for example, inAnnou et al. U.S. Pat. No. 5,638,254, Watanabe et al. U.S. Pat. No.5,543,597, both of which are incorporated by reference herein in theirentireties.

The switchgear circuits may include a resistor or other current-limitingcircuit arranged to function as fault current limiters, lighteningarresters, surge suppressors, and/or active grounding device. Further,the resistor may be coupled to suitable heat sinking elements that canabsorb heat generated by current flow. The suitable heat sinkingelements may be made of non-conducting materials, which have highspecific heats (e.g., magnesium oxide, etc.), and/or phase-changematerials, which absorb heat by phase change (e.g., melting, boiling, orsublimation). The phase change materials in a heat sinking element maybe in thermal diffusion coupling to the resistor during currentexcursions. For this purpose, the resistor may have a finely dividedcurrent-flow path intermixed with the phase-change material. Further,heat sinking elements based on boiling or sublimation may have vaporchannels to allow vapor to escape.

Conversely, the switchgear circuits may also include fusible elementsthat fuse or open circuit in response to onset of low impedance failuremodes. The fusible elements may include reactive, capacitive, and/orinductive elements.

Additionally or alternatively, the switchgear circuits may include oneor more voltage-variable resistors (varistors) arranged to protectinsulator 920 and/or power line 910 against a lightning strike or otherpower surges. The varistors may be suitably arranged across a spark gapto dissipate lightning-bolt energy without a large fractional rise inlocal voltage driven by the lightning-bolt's current-injecting action.

Further, the switchgear circuits may include a dynamically insertablecurrent limiter which is arranged to protect insulator 920 and/or powerline 910. An exemplary insertable current limiter may be arranged to beinserted in series with insulator 920. The insertable current limitermay have functionality which is the same or similar the functionality ofcurrent limiters described, for example, in Knauer U.S. Pat. No.3,982,158, and Barkan U.S. Pat. No. 4,184,186, both of which areincorporated by reference herein in their entireties.

In another exemplary implementation of insulator assembly 900 (FIG. 9B),device 930 includes an EMF source or sink 932 (e.g., a battery,capacitor, etc.) coupled to a suitable inverter circuit. The invertercircuit may be configured to inject power into or sink power from powerline 910, for example, to control power flow therein.

Additionally or alternatively, device 930 may include an activeimpedance module 934, which can be inductively coupled to power line 910to inject a positive impedance, a negative impedance, and/or a voltagein power line 910. Active impedance module 934 may be configured tocontrollably couple a voltage source (e.g., source 932) via atransformer to individual phase-lines (e.g., line 910) of a transmissionline. Active impedance module 934 may, for example, be a floatingelectrically isolated active impedance module that has functionalitieswhich are the same or similar to the functionalities of an impedancemodule described, for example, in Divan et al. U.S. Pat. No. 7,105,952.

Additionally or alternatively, device 930 may include a transformlessreactive compensation device 936. Transformless reactive compensationdevice 936 may be arranged to switchably introduce compensation in powerline or insulator paths to control current values. Transformlessreactive compensation device 936 may have functionalities which are thesame or similar to the functionalities of a reactive series compensationdevice, which is described, for example, in Fujii et al. U.S. Pat. No.6,242,895. Device 930 may further include suitable controller circuitsfor using transformless reactive compensation device 936 for singlephase or multi-phase control.

Additionally or alternatively, device 930 may include a compensationgenerator 938, which can be switchably controlled to generate a voltagehaving a phase orthogonal to a phase of a power line current and/or togenerate voltages for compensating voltage drops. Compensation generator938 may have functionalities which are the same or similar to thefunctionalities of a series compensation generator, which is described,for example, in Mizutani et al. U.S. Pat. No. 6,172,488. In particular,compensation generator 938 may be configured to regulate an equivalentreactance of a power line and/or suppress power oscillations in theline.

With renewed reference to FIG. 9A, switch S may be any suitablemechanical, electro-mechanical or electronic switch. Switch S may, forexample, be a solid-state switch, a semiconductor-based switch, aphoto-activated switch, an intrinsic silicon switch with photoinjection,an SCR, an IGBT, a thyristor, a gas-or-vacuum based switch, acrossed-field switch, an optoelectronic switch and/or an Austin-switch.Switch S may be apart of device 930 itself.

Switch S may be operated to switch insulator assembly 900 from itsnormal state as insulator 920 for electrically isolating power line 910to its activated state as device 930 in parallel to insulator 920.Switch S may be a fast acting switch having switching actions occurringon power cycle or subcycle time scales. In operation, Switch S may beoperated locally or remotely to activate device 930 to control powerquality, reliability, efficiency, uptime, and safety.

FIG. 10 shows an exemplary power delivery system 1000 utilizingintegrated insulator assembly 900 to control power quality, reliability,efficiency, uptime, and/or safety. System 1000 includes powertransmission lines 510 supported by one or more integrated insulatorassemblies 900, which are coupled to measurement devices, probes andsensors (e.g., measurement devices 1030). Measurement devices 1030 maybe coupled to a signal or data processing circuit 1040. Further, system1000 may include a controller 1050 configured to coordinate operation ofinsulator assemblies 900, measurement devices 1030, processing circuit1040 and other internal and external devices. Controller 1050 may haveany suitable mechanical or electromechanical structure, and include anoptional user interface.

Measurement devices 1030, like measurement devices 530 (FIG. 5), mayinclude sensors configured to monitor insulator, line conditions and/orweather conditions or events. The measured properties may, for example,include one or more of absorption currents, capacitive chargingcurrents, leakage currents, line currents and phase, capacitance,resistance, switching or lightning impulse voltage responses, and/ortemperature. Further, measurement devices 1030, like measurement devices530, may be interconnected to processing circuits and other internal orexternal devices (e.g., processing circuit 1040, controller 1050, statusindicators, displays, etc.) using any suitable approaches includingoptical, electrical, wireless, pneumatic, and/or mechanical approaches.Processing circuit 1040 may be configured to receive and process dataand/or signals from one or more measurement devices 1030 over theinterconnections. Processing circuit 1040 may include any suitablecombination of hardware and software for processing the data and/orsignals. Processing circuit 1040 may determine operation of an insulatorassembly 900 including operation of switch S and device 920. Processingcircuit 1040 may include a decision making algorithm or routineconfigured to supervise operation of insulator assembly 900 forsourcing, sinking and dispatching of real and/or reactive power in orderto meet load demands on system 1000. The algorithm may determine system1000 and/or insulator assembly 900 responses to faults, transient eventsand/or steady-state operation. Processing circuit 1040 may be configuredto report measurement data and processing results to other devices(e.g., controller 1050) and/or users.

One or more components or portions of system 1000 including measuringdevices 1030, processing circuit 1040 and controller 1050 may be placedin or about insulator assemblies 900 (e.g., in physical cavities orportions of insulator 920). Alternatively or additionally, one or morecomponents or portions of system 1000 may be placed in operationalproximity in or about insulator assemblies 900 or at remote locations.One or more components of processing circuit 1040 and/or controller 1050may, for example, be located in a remote building or facility and linkedwith system 1000 components through wireless, wired, IP protocol orother approaches.

FIG. 11 shows exemplary features of a method 1100 for sourcing, sinkingand dispatching of real and/or reactive power in order to meet loaddemands on power delivery system. Method 1100 utilizes an insulatorassembly (e.g., assembly 900), which has two states—an insulator stateand a parallel device state, to modify or regulate power delivery systemparameters (e.g., series impedance, shunt impedance, phase angle, andoccurrence of sub harmonic oscillations). Method 1100 includes deployingan insulator assembly, which is switchable between a normal isolatingstate and a reactive or conducting active state, to isolate a power line(1110), sensing a power delivery system condition (1120), and switchingthe insulator assembly to its active “conducting” state to source, sinkand/or dispatch real and/or reactive power on the power delivery system(1130).

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thesummary, detailed description, drawings, and claims are not meant to belimiting. Other embodiments may be utilized, and other changes may bemade, without departing from the spirit or scope of the subject matterpresented here. Those having skill in the art will recognize that thestate of the art has progressed to the point where there is littledistinction left between hardware and software implementations ofaspects of systems; the use of hardware or software is generally (butnot always, in that in certain contexts the choice between hardware andsoftware can become significant) a design choice representing cost vs.efficiency tradeoffs. Those having skill in the art will appreciate thatthere are various vehicles by which processes and/or systems and/orother technologies described herein can be effected (e.g., hardware,software, and/or firmware), and that the preferred vehicle will varywith the context in which the processes and/or systems and/or othertechnologies are deployed. For example, if an implementer determinesthat speed and accuracy are paramount, the implementer may opt for amainly hardware and/or firmware vehicle; alternatively, if flexibilityis paramount, the implementer may opt for a mainly softwareimplementation; or, yet again alternatively, the implementer may opt forsome combination of hardware, software, and/or firmware. Hence, thereare several possible vehicles by which the processes and/or devicesand/or other technologies described herein may be effected, none ofwhich is inherently superior to the other in that any vehicle to beutilized is a choice dependent upon the context in which the vehiclewill be deployed and the specific concerns (e.g., speed, flexibility, orpredictability) of the implementer, any of which may vary. Those skilledin the art will recognize that optical aspects of implementations willtypically employ optically-oriented hardware, software, and or firmware.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, flowcharts,and/or examples. Insofar as such block diagrams, flowcharts, and/orexamples contain one or more functions and/or operations, it will beunderstood by those within the art that each function and/or operationwithin such block diagrams, flowcharts, or examples can be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or virtually any combination thereof. In one embodiment,several portions of the subject matter described herein may beimplemented via Application Specific Integrated Circuits (ASICs), FieldProgrammable Gate Arrays (FPGAs), digital signal processing circuits(DSPs), or other integrated formats. However, those skilled in the artwill recognize that some aspects of the embodiments disclosed herein, inwhole or in part, can be equivalently implemented in integratedcircuits, as one or more computer programs running on one or morecomputers (e.g., as one or more programs running on one or more computersystems), as one or more programs running on one or more processingcircuits (e.g., as one or more programs running on one or moremicroprocessors), as firmware, or as virtually any combination thereof,and that designing the circuitry and/or writing the code for thesoftware and or firmware would be well within the skill of one of skillin the art in light of this disclosure. In addition, those skilled inthe art will appreciate that the mechanisms of the subject matterdescribed herein are capable of being distributed as a program productin a variety of forms, and that an illustrative embodiment of thesubject matter described herein applies regardless of the particulartype of signal bearing medium used to actually carry out thedistribution. Examples of a signal bearing medium include, but are notlimited to, the following: a recordable type medium such as a floppydisk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk(DVD), a digital tape, a computer memory, etc.; and a transmission typemedium such as a digital and/or an analog communication medium (e.g., afiber optic cable, a waveguide, a wired communications link, a wirelesscommunication link, etc.). Further, those skilled in the art willrecognize that the mechanical structures disclosed are exemplarystructures and many other forms and materials may be employed inconstructing such structures.

In a general sense, those skilled in the art will recognize that thevarious embodiments described herein can be implemented, individuallyand/or collectively, by various types of electro-mechanical systemshaving a wide range of electrical components such as hardware, software,firmware, or virtually any combination thereof; and a wide range ofcomponents that may impart mechanical force or motion such as rigidbodies, spring or torsional bodies, hydraulics, and electro-magneticallyactuated devices, or virtually any combination thereof. Consequently, asused herein “electro-mechanical system” includes, but is not limited to,electrical circuitry operably coupled with a transducer (e.g., anactuator, a motor, a piezoelectric crystal, etc.), electrical circuitryhaving at least one discrete electrical circuit, electrical circuitryhaving at least one integrated circuit, electrical circuitry having atleast one application specific integrated circuit, electrical circuitryforming a general purpose computing device configured by a computerprogram (e.g., a general purpose computer configured by a computerprogram which at least partially carries out processes and/or devicesdescribed herein, or a microprocessor configured by a computer programwhich at least partially carries out processes and/or devices describedherein), electrical circuitry forming a memory device (e.g., forms ofrandom access memory), electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, or optical-electricalequipment), and any non-electrical analog thereto, such as optical orother analogs. Those skilled in the art will also appreciate thatexamples of electro-mechanical systems include but are not limited to avariety of consumer electronics systems, as well as other systems suchas motorized transport systems, factory automation systems, securitysystems, and communication/computing systems. Those skilled in the artwill recognize that electro-mechanical as used herein is not necessarilylimited to a system that has both electrical and mechanical actuationexcept as context may dictate otherwise.

In a general sense, those skilled in the art will recognize that thevarious aspects described herein which can be implemented, individuallyand/or collectively, by a wide range of hardware, software, firmware, orany combination thereof can be viewed as being composed of various typesof “electrical circuitry.” Consequently, as used herein “electricalcircuitry” includes, but is not limited to, electrical circuitry havingat least one discrete electrical circuit, electrical circuitry having atleast one integrated circuit, electrical circuitry having at least oneapplication specific integrated circuit, electrical circuitry forming ageneral purpose computing device configured by a computer program (e.g.,a general purpose computer configured by a computer program which atleast partially carries out processes and/or devices described herein,or a microprocessor configured by a computer program which at leastpartially carries out processes and/or devices described herein),electrical circuitry forming a memory device (e.g., forms of randomaccess memory), and/or electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, or optical-electricalequipment). Those having skill in the art will recognize that thesubject matter described herein may be implemented in an analog ordigital fashion or some combination thereof.

Those skilled in the art will recognize that it is common within the artto implement devices and/or processes and/or systems in the fashion(s)set forth herein, and thereafter use engineering and/or businesspractices to integrate such implemented devices and/or processes and/orsystems into more comprehensive devices and/or processes and/or systems.That is, at least a portion of the devices and/or processes and/orsystems described herein can be integrated into other devices and/orprocesses and/or systems via a reasonable amount of experimentation.Those having skill in the art will recognize that examples of such otherdevices and/or processes and/or systems might include—as appropriate tocontext and application—all or part of devices and/or processes and/orsystems for generation, transmission and distribution of electricalpower, a communications system (e.g., a networked system, a telephonesystem, a Voice over IP system, wired/wireless services, etc.).

One skilled in the art will recognize that the herein describedcomponents (e.g., steps), devices, and objects and the discussionaccompanying them are used as examples for the sake of conceptualclarity and that various configuration modifications are within theskill of those in the art. Consequently, as used herein, the specificexemplars set forth and the accompanying discussion are intended to berepresentative of their more general classes. In general, use of anyspecific exemplar herein is also intended to be representative of itsclass, and the non-inclusion of such specific components (e.g., steps),devices, and objects herein should not be taken as indicating thatlimitation is desired.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations are not expressly set forth herein for sakeof clarity.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely exemplary, and that in fact many other architectures can beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality can be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected”, or“operably coupled”, to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable”, to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents and/or wirelessly interactable and/or wirelessly interactingcomponents and/or logically interacting and/or logically interactablecomponents.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from the subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true spirit and scope of the subject matter described herein.Furthermore, it is to be understood that the invention is defined by theappended claims. It will be understood by those within the art that, ingeneral, terms used herein, and especially in the appended claims (e.g.,bodies of the appended claims) are generally intended as “open” terms(e.g., the term “including” should be interpreted as “including but notlimited to,” the term “having” should be interpreted as “having atleast,” the term “includes” should be interpreted as “includes but isnot limited to,” etc.). It will be further understood by those withinthe art that if a specific number of an introduced claim recitation isintended, such an intent will be explicitly recited in the claim, and inthe absence of such recitation no such intent is present. For example,as an aid to understanding, the following appended claims may containusage of the introductory phrases “at least one” and “one or more” tointroduce claim recitations. However, the use of such phrases should notbe construed to imply that the introduction of a claim recitation by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim recitation to inventions containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.”

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.For example, FIG. 12 shows a power line system component 1200 withtemperature control or limiting features. Component 1200 includes acurrent carrying resistive element (e.g., resistor 1210). The resistiveelement may have linear or non-linear characteristics. Resistor 1210may, for example, be a part of a current limiter, a lightning arrester,a surge suppressor, and/or an active grounding device. In particular,resistor 1210 may be a part of a switchable conductance placed inparallel with a power line insulator. In component 1200, resistor 1210may be thermally coupled to heat sink 1220 made of material 1230 thatabsorbs heat by phase change.

Material 1230 may be electrically non-conductive. Heat sink 1220 andresistor 1210 may be co-disposed so that current carrying paths in thelatter are adjoining or intermixed with material 1230 in the former.Material 1230 may absorb heat by melting, boiling, and/or sublimation.Heat sink 1220 may optionally include channels 1240 which allow escapeof phase-changed material (e.g., vapor or fluids).

Further, for example, FIGS. 13A and 13B shows exemplary power deliverysystem components 1300A and 1300B configured to electrically isolate ahigh voltage power transmission line from another power line, ground orground equivalent, and/or a neutral line. An end of an exemplary powerdelivery system component (1300A/B) may be indirectly connectable to thehigh voltage power transmission line (e.g., via a transformer).Components 1300A/B may include a virtual reactance.

Components 1300A/B may include various arrangements of suitableinsulator bodies 1340 in series with inductive elements 1320 and/orreactive elements 1330 (hereinafter, collectively “reactive circuits1320/30”). Portions of a reactive circuit and insulator body 1340 may bemay co-disposed in a common physical structure. An end of a reactivecircuit 1320/30 and/or an insulator body 1340 may be connectable thehigh voltage power transmission line. Further, one or more electricalcircuit elements may be disposed in series and/or in parallel withreactive circuit 1320/30. The electrical circuit elements may, forexample, include a portion of an active impedance module, a groundingswitch, a lightning arrestor, a surge arrestor, an active groundingdevice, a dynamically insertable current limiter, an inverter, atransformerless reactive compensation device, a phase angle regulator, avariable series capacitor, a static VAR compensator, a varistor, a Zenerdiode, a nonlinear resistor, and/or a braking resistor.

Components 1300A/B may be variously configured to limit current flowthrough an insulator element 1340, inject power into and/or sink powerfrom the high voltage power transmission line, and/or to introducecompensation in the high voltage power transmission line and/orinsulator path to control current values (e.g., for single phase ormulti-phase control). The components may be configured to generate avoltage having a phase substantially orthogonal to a phase of a powerline current, generate voltages for compensating voltage drops in thepower line, and/or regulate an equivalent reactance of the power lineand/or suppress power oscillations in the power line.

An exemplary power delivery system may deploy suitable insulatorelement/reactive circuit combinations (e.g., components 1300A/B) toelectrically isolate a high voltage power transmission line (e.g., agreater than about 70 kV power line), from another power line, ground orground equivalent and/or a neutral line. The reactive circuits may beconfigured to inject power into and/or sink power from the high voltagepower transmission line introduce compensation in the high voltage powertransmission line and/or insulator path to control current values (e.g.,in the high voltage power transmission line and/or insulator path forsingle phase or multi-phase control), generate a voltage having a phasesubstantially orthogonal to a phase of a power line current and/or togenerate voltages for compensating voltage drops in the power line,and/or regulate an equivalent reactance of the power line and/orsuppress power oscillations in the power line.

FIG. 13C shows an exemplary method 1350 for operating a power deliverysystem which uses insulator element/reactive circuit combinations (e.g.,components 1300A/B) to electrically isolate a high voltage powertransmission line. Method 1350 includes sensing a power line conditionor parameter (1352), and in response, operating the reactive circuitdeployed in series with the at least one insulator element (1354).

Sensing a power line condition or parameter (1352) may, for example,include sensing a power line condition or parameter that comprisessensing a breakdown or an anticipated breakdown of the at least oneinsulator element, sensing a rising voltage across the at least oneinsulator element, sensing or predicting a voltage rise due to measuredproperties elsewhere on the power line and/or predicting an imminentlightning strike and/or atmospheric potential disturbance.

Operating the reactive circuit (1354) may include, for example,operating a plurality of reactive circuits deployed in series with arespective plurality of insulator elements for distributed sourcing,sinking, and/or dispatching real and/or reactive power on the powerline, modifying a power line series impedance and/or shunt impedance,introducing a virtual reactance in the power line, modifying a powerline phase angle, modifying an occurrence of sub harmonic oscillationson the power line, and/or limiting a current flow across the at leastone insulator element. Limiting a current flow across the at least oneinsulator element may include, for example, diverting the currentthrough a current limiter, a lightning arrester, a surge suppressor,and/or a grounding device, and/or a selected combination of a resistivecircuit and/or a reactive element to dissipate power. Limiting a currentflow across the at least one insulator element also may, for example,include diverting a current through a resistive device, resistor, and/orvaristor, which are thermally coupled to a heat sink to dissipate realpower. The heat sink may be made of materials that undergo a phasechange to absorb heat (as shown e.g., FIG. 12).

Additionally or alternatively, operating the reactive circuit (1354)may, for example, include, indirectly or directly coupling the reactivecircuit to the power line. introducing reactive compensation in thepower line and/or an insulator path for single phase or multi-phasecontrol, generating a voltage having a phase substantially orthogonal toa phase of the power line current, generating voltages for compensatingvoltage drops in the power line, regulating an equivalent reactance ofthe power line and/or suppressing power oscillations in the power line,coupling an EMF-source and/or sink to the power line, and/or activatinga circuit element that is configured to open circuit in response to anonset of a low-impedance failure mode.

Further, for example, FIGS. 14A and 14B respectively show an exemplarypower delivery system 1400A and an exemplary method 1400B for measuringcharacteristics of power delivery system including the voltage/currentcapabilities of line components.

Power delivery system 1400A may include a power transmission network(1410) having a plurality of independent power transmission lines, eachhaving a respective preset voltage rating or power capacities. System1400A includes a first 1430 and a second circuitry 1440 configured toapply a voltage pulse to an insulator in use to electrically isolate alive power line and to measure insulator responses, respectively. Theapplied voltage pulse may have high frequency components so that theresponse of an insulator is substantially independent of properties ofthe live power line.

First circuitry 1430 may be configured to apply a variable amplitudeelectrical pulse between about a power line gripping end and an oppositeend of the insulator in use to electrically isolate the powertransmission line, for example, at about times corresponding to zerovoltage crossing times in the power transmission line. The variableamplitude electrical pulse may be applied ahead of a zero voltagecrossing, which may correspond to a situation where the insulatorundergoes a reversal in the polarity of voltages across it duringtesting.

Second circuitry 1440 may be configured to measure a response to anapplied variable amplitude electrical pulse on a time scale that is afraction of a power cycle in the power transmission line, and duringselect portions of power cycles properties in which properties of apower line gripping end of the insulator are, for example, substantiallyindependent or decoupled from power flowing in power transmission line.

System 1400A may include additional or alternative measurement devices(e.g., Measurement Probes/Devices/Sensors 530), which may be in physicalor sensing contact with the insulators, and any suitable data and/orsignal processing circuitry (e.g., data and/or signal processingcircuitry 540). Measurement Probes/Devices/Sensors 530 and/or secondcircuitry 1440 may be configured to estimate a voltage standoffcapability of an insulator in use. The estimated voltage standoffcapability may be a present-time and/or a future-time standoff voltagecapability.

Like the components of system 500, the components of system 1400A may beconfigured to evaluate or determine the actual voltage ratings or powercapacities of the independent power transmission lines in use. Theseactual voltage ratings or capabilities may be different than presetvoltage ratings or power capacities of the lines.

System 1400A may further include a controller (1420), which isconfigured to receive measured actual voltage capabilities of one ormore of the plurality of independent power transmission lines in use.Controller 1420 may be further configured to dispatch power over theplurality of independent power transmission lines according to themeasured actual voltage capabilities of the one or more independentpower transmission lines in use.

In a version of system 1400A, system components may be configured tomeasure the voltage capabilities of several of insulators simultaneouslyor at about the same time. In this version, system components (e.g.,first and second circuitries 1430 and 1440) may be configured to apply avoltage pulse to an end of section of a power transmission line isolatedby a number of insulators measure the properties of more than oneinsulator supporting a power line. The voltage pulse width orfrequencies may be suitably tailored to isolate the section of the powertransmission line, and properties of the number of insulators supportingthe isolated section may be determined by measuring reflected responsesof the number of insulators to the applied voltage pulse. A suitablytailored applied voltage pulse for this purpose may have a frequency ofabout 1 KHz.

With reference to FIG. 14B, method 1400B may include applying a voltagepulse (e.g., variable amplitude pulse) to an insulator in use toelectrically isolate a live power line (1452), and measuring a responseof the insulator to the applied voltage pulse (1454). The appliedvoltage pulse may be applied between about a power line gripping end andan opposite end of the insulator in use to electrically isolate thepower transmission line. Further, the applied voltage pulse may havehigh frequency components so that the response of the insulator issubstantially independent or isolated from properties of the live powerline (e.g., because of its inductance). The applied voltage pulse may beapplied at about times corresponding to zero voltage crossing times inthe power transmission line (e.g., ahead, behind, or straddling a zerovoltage crossing). Measuring a response of the insulator to the appliedvoltage pulse (1454) may, for example, include measuring a response toan applied variable amplitude electrical pulse on a time scale that is afraction of a power cycle in the power transmission line, measuringinsulator properties during select portions of power cycles in whichproperties of a power line gripping end of the insulator aresubstantially independent or decoupled from power flowing in powertransmission line.

FIG. 15 shows an exemplary method 1500 for dispatching power overmulti-line power transmission system (e.g., systems 200, 500, 800, 1000,1400A, etc.) in which each line has a preset voltage rating or powercarrying capability. Under some situations or conditions, an actualpower capability of a transmission line may be a trivial 0% or 100% ofthe preset voltage rating or power carrying capability. In practicalsituations, it is likely that the actual power capability of atransmission line may be a substantial or non-trivial fraction (e.g., 1%to 99%) or multiple (e.g., >1.01) of the preset voltage rating or powercarrying capability. Method 1500 includes measuring actual voltagecapabilities of one or more of the plurality of independent powertransmission lines in use (1552), and dispatching power over theplurality of independent power transmission lines according to themeasured actual voltage capabilities of the one or more independentpower transmission lines in use (1554). Measuring actual voltage ratingsor power carrying capabilities 1552 may be accomplished by employing anysuitable method (e.g., method 1400B). Method 1500 may be applied todynamically optimize dispatching power over and/or loading of powerlines over a range of non-trivial actual conditions in a multi-linepower transmission system (e.g., under which an actual power capabilityof a transmission line is not a trivial 0% or 100% of power rating).

Further, it will be understood that the various devices and devicecomponents described herein may be made using any suitable manufacturingor fabrication technologies. For example, devices and device components(e.g., surface reconditioner 230, sensor 240, heaters, electrodes A andB, electrical and/or mechanical sensors, measurement devices 530,processing circuit 540, switches S, measurement device 720, device 930,resistive, reactive elements, measurement devices 1030, signal or dataprocessing circuit 1040, circuits, switchable conductances, component1200, etc) that are co-disposed with insulator elements may befabricated by depositing and patterning conductive thin films oninsulator surfaces. Exemplary conductances or other circuits elements bemade from electrically conducting coating materials (e.g., indium tinoxide) applied to glass and other ceramic insulator bodies.

The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopeand spirit being indicated by the following claims.

1. A method, comprising: in a power transmission network having aplurality of independent power transmission lines, each having arespective preset voltage rating, measuring actual voltage capabilitiesof one or more of the plurality of independent power transmission linesin use; and dispatching power over the plurality of independent powertransmission lines according to the measured actual voltage capabilitiesof the one or more independent power transmission lines in use.
 2. Themethod of claim 1, wherein measuring actual voltage capabilities of oneor more of the plurality of independent power transmission lines in usecomprises: applying a voltage pulse to an insulator in use toelectrically isolate a live power line; and measuring a response of theinsulator to the applied voltage pulse, wherein the voltage pulse hashigh frequency components so that the response of the insulator issubstantially independent of properties of the live power line.
 3. Themethod of claim 2, wherein an inductance of the live power linesubstantially isolates the response of the insulator from properties ofthe live power line.
 4. The method of claim 2, further comprising,applying a variable amplitude electrical pulse between about a powerline gripping end and an opposite end of the insulator in use toelectrically isolate the live power line.
 5. The method of claim 2,further comprising, applying a variable amplitude electrical pulse atabout times corresponding to zero voltage crossing times in the livepower line.
 6. The method of claim 2, wherein applying a variableamplitude electrical pulse comprises applying the variable amplitudeelectrical pulse ahead of a zero voltage crossing.
 7. The method ofclaim 2, further comprising, measuring a response to an applied variableamplitude electrical pulse on a time scale that is a fraction of a powercycle in the live power line.
 8. The method of claim 2, furthercomprising, measuring insulator properties during select portions ofpower cycles, wherein during the select portions of the power cyclesproperties of a power line gripping end of the insulator aresubstantially independent or decoupled from power flowing in the livepower line.
 9. The method of claim 2, further comprising, reportingmeasured insulator properties to an external device, controller, and/ordisplay.
 10. The method of claim 1, wherein measuring actual voltagecapabilities of one or more of the plurality of independent powertransmission lines in use comprises: applying a voltage pulse to an endof section of a power transmission line isolated by a number ofinsulators; and measuring reflected responses of the number ofinsulators to the applied voltage pulse.
 11. The method of claim 10,wherein applying a voltage pulse comprises applying a voltage pulsehaving a frequency of about 1 KHz.
 12. A system, comprising: acontroller arranged to dispatch power in a power transmission networkhaving a plurality of independent power transmission lines, each havinga respective preset voltage rating, wherein the controller is configuredto receive measured actual voltage capabilities of one or more of theplurality of independent power transmission lines in use, and whereinthe controller is configured to dispatch power over the plurality ofindependent power transmission lines according to the measured actualvoltage capabilities of the one or more independent power transmissionlines in use.
 13. The system of claim 12, further comprising: a firstcircuitry to apply a voltage pulse to an insulator in use toelectrically isolate a live power line; and a second circuitry tomeasure a response of the insulator to the applied voltage pulse,wherein the applied voltage pulse has high frequency components so thatthe response of the insulator is substantially independent of propertiesof the live power line.
 14. The system of claim 13, wherein the firstcircuitry is configured to apply a variable amplitude electrical pulsebetween about a power line gripping end and an opposite end of theinsulator in use to electrically isolate the live power line.
 15. Thesystem of claim 13, wherein the first circuitry is configured to apply avariable amplitude electrical pulse at about times corresponding to zerovoltage crossing times in the live power line.
 16. The method of claim13, wherein applying a variable amplitude electrical pulse comprisesapplying the variable amplitude electrical pulse ahead of a zero voltagecrossing.
 17. The system of claim 13, wherein the second circuitry isconfigured to measure a response to an applied variable amplitudeelectrical pulse on a time scale that is a fraction of a power cycle inthe live power line.
 18. The system of claim 13, wherein the secondcircuitry is configured to measure insulator properties during selectportions of power cycles, wherein during the select portions of thepower cycles properties of a power line gripping end of the insulatorare substantially independent or decoupled from power flowing in thelive power line.
 19. The system of claim 12, further comprising: aninsulator arranged to electrically isolate a power transmission line;and a device in physical contact with the insulator, wherein the deviceis arranged to determine properties of the insulator in use toelectrically isolate the power transmission line.
 20. The system ofclaim 19, wherein at least a portion of the device is disposed within abody of the insulator.
 21. The system of claim 19, wherein the device isarranged to estimate a voltage standoff capability of the insulator inuse.
 22. The system of claim 19, wherein the device is arranged tomeasure one or more of absorption currents, capacitive chargingcurrents, leakage currents, capacitance, resistance, dielectricabsorption (DA), polarization index (PI), high potential or hipot (highvoltage) and step voltage responses, switching or lightning impulsevoltage responses, and/or temperature of at least a portion of theinsulator in use.
 23. The system of claim 19, wherein the device isarranged to conduct water penetration tests including one or more ofhardness, steep-front impulse voltage, and power frequency voltage testson the insulator in use.
 24. The system of claim 19, wherein the deviceis arranged to conduct one or more of low-frequency dry flashover tests,low-frequency wet flashover tests, critical impulse flashover tests,radio-influence voltage and/or salt fog-like tests on the insulator inuse.
 25. The system of claim 19, wherein the device is arranged tooptically evaluate surface properties including one or more of chalking,crazing, dry bands, tracking and/or erosion of the insulator in use. 26.The system of claim 12, wherein the device is configured to apply avariable amplitude electrical pulse ahead of a zero voltage crossing.27. The method of claim 12, wherein measuring actual voltagecapabilities of one or more of the plurality of independent powertransmission lines in use comprises: applying a voltage pulse to an endof section of a power transmission line isolated by a number ofinsulators; and measuring reflected responses of the number ofinsulators to the applied voltage pulse.
 28. The method of claim 27,wherein applying a voltage pulse comprises applying a voltage pulsehaving a frequency of about 1 KHz.
 29. The system of claim 19, whereinthe device is arranged to measure a resistance or conductance of atleast a portion of the insulator in use.
 30. The system of claim 19,wherein the device is arranged to measure one or more DC properties ofthe insulator in use.
 31. The system of claim 19, wherein the device isarranged to measure one or more frequency-dependent properties of theinsulator in use.
 32. The system of claim 19, wherein the device isarranged to measure ambient power line leakage currents across theinsulator.
 33. The system of claim 19, wherein the device is arranged tomeasure leakage currents across the insulator in response to testexcitations.
 34. The system of claim 19, wherein the device is arrangedto measure leakage currents across the insulator in response to testexcitations that are a nominal power line frequency.
 35. The system ofclaim 19, wherein the device is arranged to measure leakage currentsacross the insulator in response to test excitations that are at higherfrequency than a nominal power line frequency.
 36. The system of claim19, wherein the device is arranged to measure electrical potentials orfields on or proximate to the insulator in use under ambient power lineconditions.
 37. The system of claim 19, wherein the device is arrangedto measure electrical potentials or fields on or proximate to theinsulator in use in response to test excitations.
 38. The system ofclaim 19, wherein the device is arranged to measure electricalpotentials or fields on or proximate to the insulator in use in responseto test excitations that are at higher frequency than a nominal powerline frequency.
 39. The system of claim 19, wherein the device comprisescircuitry configured to estimate a standoff voltage capability of theinsulator in use based on insulator properties measured by the device.40. The system of claim 19, wherein the device comprises circuitryconfigured to estimate a present-time and/or a future-time standoffvoltage capability of the insulator in use based on insulator propertiesmeasured by the device.
 41. The system of claim 19, wherein the devicecomprises circuitry configured to provide a time-to-failure estimate forthe insulator in use based on insulator properties measured by thedevice.
 42. The system of claim 19, further comprising, circuitrycoupled to the device, wherein the circuitry is configured to report astatus or condition of the insulator in use based on insulatorproperties measured by the device.
 43. The system of claim 42, whereinthe circuitry is configured to report a status or condition of theinsulator in use in response to at least one of a schedule, a present orpredicted insulator condition or property value, a user query, and/or aweather event.
 44. The system of claim 42, wherein the circuitry isconfigured to compute and report a present and/or a future condition orproperty value for the insulator in use.
 45. The system of claim 42,wherein the circuitry is configured to compute and report atime-to-failure and/or a recommended maintenance schedule for theinsulator in use.
 46. The system of claim 19, wherein the device isconfigured to apply a variable amplitude electrical pulse between abouta power line gripping end and an opposite end of the insulator in use toelectrically isolate the power transmission line.
 47. The system ofclaim 19, wherein the device is configured to apply a variable amplitudeelectrical pulse at about times corresponding to zero voltage crossingsin the power transmission line.
 48. The system of claim 19, wherein thedevice is configured to measure a response to an applied variableamplitude electrical pulse on a time scale that is a fraction of a powercycle in the power transmission line.
 49. The system of claim 19,wherein the device is further configured to measure insulator propertiesduring a time interval about a voltage zero crossing in the powertransmission line and wherein during the time interval properties of apower-line gripping end of the insulator are substantially independentor decoupled from power flowing in the power transmission line.
 50. Thesystem of claim 19, wherein the device is further configured to measureinsulator properties during select portions of a power cycle in thepower transmission line, wherein during the select portion of the powercycle properties of a power line gripping end of the insulator aresubstantially independent or decoupled from power flowing in the powertransmission line.
 51. The system of claim 19, further comprisingcircuitry arranged to report measured insulator properties to thecontroller.